Actually the list he faced in finals WAS a good counter to it, with Corran and Poe plus blocker.
Just that Corran completely blanked for two turns, which can happen but it's quite rare.
You can kill Heavers Poe pretty fast with that list, and after that the list has not much left to fear. The stresswing is the main reason you can lose the matchup, but you could actually try and yolo Poe with your two aces. Nathan didn't do it and got punished by bad luck, but i actually liked his list much more.